1. Field of the Invention
Present invention relates to a susceptor device which is preferably used for fixing a plate sample such as a silicon wafer in a semiconductor manufacturing device for manufacturing a semiconductor device such as an IC (Integrated Circuit), LSI (Large Scale Integration), and a VLSI (Very Large Scale Integration). In particular, the present invention relates to a susceptor device which can maintain a temperature in a plate sample which is mounted on a mounting surface in the susceptor device at a predetermined temperature efficiently such that the susceptor device does not cause a contamination to the plate sample nor generates a particle with a superior durability.
2. Description of Related Art
Conventionally, for example, a susceptor base body is used for a member for mounting the plate sample when various processes are performed to the plate sample such as a silicon wafer in processes for manufacturing a semiconductor device such as an IC, an LSI, and a VLSI.
When an etching process is performed to the plate sample, for example, under a plasma atmospheric condition, there occurs a problem in that a temperature of a surface of the plate sample becomes high by a plasma heat; thus, a resist layer on the surface bursts. In order to deal with this problem, a susceptor device is used in which a temperature controlling section in which a flow path for circulating a temperature controlling medium is formed is attached unitarily to a bottom surface of the susceptor base body on which the plate sample is mounted so as to exchange a heat by circulating a cooling medium in the flow path in the temperature controlling section and maintain the temperature of the plate sample at a predetermined temperature desirably.
FIG. 5 is a cross section of an example for such a susceptor device. Here, a susceptor device 1 comprises a ceramic susceptor base body 2 of which upper surface is a mounting surface 2a for mounting a plate sample, an electrode 3 which is disposed inside of the susceptor base body 2, a power supplying terminal 5 which is disposed in a fixing hole 4 in the susceptor base body 2 and connected to the electrode 3, a temperature controlling section 6 which is disposed beneath the susceptor base body 2 so as to support the susceptor base body 2 from downward having a flow path 6a for circulating medium such as a cooling medium thereinside. The susceptor base body 2 and the temperature controlling section 6 are attached unitarily via an adhesive layer 7 which is made of a cementing agent which contains a soft blazing filler metal such as an Indium and an Indium alloy.
The power supplying terminal 5 is connected to a high frequency power supply 11 which is disposed thereoutside and a direct current power supply 13 and a condenser 12 via coils 14 respectively.
The electrode 3 is any one among an electrostatic absorbing electrode, a plasma generating electrode, or an electrode which can serve as an electrostatic absorbing electrode and a plasma generating electrode compatibly.
However, in a conventional susceptor device 1 which is explained above, the adhesive layer 7 for attaching the susceptor base body 2 and the temperature controlling section 6 unitarily does not have a sufficient durability to a corrosive gas or a plasma. Therefore, there is a concern that the adhesive layer 7 is always exposed to such a corrosive gas and a plasma; thus, the adhesive layer 7 becomes deteriorated. Thus, there is a problem in that a thermal conductivity in the adhesive layer 7 is deteriorated; thus, it is difficult to control a temperature in the plate sample at a desirable constant temperature.
Also, there is a concern that the plate sample is contaminated and a particle is generated because a peripheral section of the adhesive layer 7 is exposed; thus a heavy metal which is contained in the adhesive layer 7 evaporates easily.
Furthermore, there is a concern that an extraordinary electric discharge occurs in the adhesive layer 7 while the adhesive layer 7 is exposed to a plasma; thus an insulating characteristics in a cemented surface is destructed because the adhesive layer 7 is conductive. Therefore, there are concerns not only that a safety device starts so frequently that the susceptor device can not hardly be operated stably but also that a stability in the susceptor device cannot be sufficient even if the susceptor device is operated stably.